Ocular axial length in homocystinuria patients with and without ocular changes: Effects of early treatment and biochemical control. Mulvihill A, O’Keefe M, Yap S, Naughten E, Howard P, Lanigan B. J AAPOS 2004;8:254–258.

Abstract

The authors evaluated all patients with homocystinuria attending the Irish National Center for Inherited Metabolic Disorders to establish whether myopia in homocystinuria could be attributable to increased ocular axial length. Ocular axial lengths were measured in a total of 27 patients (15 males and 12 females) with a mean age of 24.0 years (range, 11.8 to 36.3 years). Fourteen patients were detected by newborn screening while 13 were late detected. Eyes with no ocular pathology (28 eyes) had a mean spherical equivalent of −0.25 D and a mean axial length of 23.4 mm ± 0.9 mm. Eyes with phacodonesis or lens subluxation (12 eyes), had a mean refractive error of −10.7 D and a mean axial length of 23.8 mm ± 1.9 mm. Eyes with complete lens dislocation (12 eyes) were optically aphakic and had a mean refractive error of +12.9 D and a mean axial length of 24.9 mm ± 0.9 mm. All patients with normal eyes had good long-term metabolic control while those with ocular abnormalities did not. Eyes with complete lens dislocation had significantly longer mean axial length than normal eyes ( P = .0163). The authors concluded that ocular axial length is significantly increased in individuals with homocystinuria and lens dislocation. Increased axial length is a complication that has not been previously described in homocystinuria and may be preventable with early treatment and good biochemical control.